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(No Model.) 4 Sheets- Sheet 1.

H. BLAGKMAN. APPARATUS FOR REGOVBRING ALKALI.

No. 492,382. Patented Peb.,28, 1893. 7

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APPARATUS FOR REGOVERING ALKALI- No. 492,382} Patented Feb. 28, 1893.

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(No Model.) 4 Sheets-Sheet 3. H. BLAGKMAN. APPARATUS FOR RBGOVBRINGALKALI.

Patented Feb. 28,1893.

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(No Model.) 4 Sheets-8heet 4. H. BLAGKMAN APPARATUS FOR REGOVERINGALKALI.

No. 492,382. Patented Feb. 28, 1893.

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UNITED STATES PATENT OFFICE.

HENRY BLAOKMAN, OF NEW YORK, N. Y.

APPARATUS FOR RECOVERING ALKALI.

SPECIFICATION forming part of Letters Patent No. 492,382, dated February28, 189 3. Application filed March 31, 1891. Renewed July 26. 1892-Serial No. 441,324. (No model.)

To aZZ whom it may concern;

Be it known that I, HENRY BLAOKMAN, a citizen of the United States,residing in the city, county, and State of New York, have inventedcertain new and useful Improvements in Apparatus for Evaporating andCalcining Alkaline and other Solutions, of which the following is aspecification.

My invention providesan improved furnace designed more particularly forthe recovery of soda or other caustic alkalies fromthe refuse liquors ofpulp mills, but applicable also for the recovery of other refractorychemicals from solutions.

In recovering the refuse liquors from pulp mills it is customary tofirst concentrate the liquor and then tosubject it to calcination in afurnace whereby the ligneous, mucilaginous and other combustibleimpurities contained in the liquor are burned out, leaving the alkali ina tolerably pure condition. In the process of calcination thecombustible constituents while burning out are utilized as a portion ofthe fuel for maintaining the heat of the furnace and supplying heat foreffecting the concentration.

My improved calcining furnace is of the rotary order, that is to say,its calcining chamber consists of a horizontally arranged bar- 'relmounted to be slowly rotated and receiving through it the stream ofburning gases which act upon the alkaline material which is fed into itand caused to pass through it "from end to end. My improvements relateinpart to the mounting of the rotary calcining chamber and in part tothemeans for concentrating the liquor to prepare it for the calciningprocess.

In its preferred constructionmy improved furnace comprises a stack,chimney or upright chamber, communicating at its lower end withtheoutlet from the calcining chamber, the latter being closed at itsopposite end and provided with means for introducing burninggases to itmingled with air in proper proportionsfor maintainingcombustion therein.The alkaline solution to be concentrated is introduced into the upperpart of the chimney orstack in a showeror spray, or by streaming it downthe walls of the stack, so that in its descent it is largely evaporated,and at the bottom of the stack it falls into a concentrating tankwherein it is stirred and circulated and from which it is pumped up tobe again showered through the stack. The liquor after being sufficientlyconcentrated in this tank is caused to flow over and enters therevolving calcining chamber, wherein it is calcined, and the resultingalkali or ash is discharged therefrom atthe opposite end.

Figure l of the accompanying drawings is a side elevation of my'improvedapparatus partlyin vertical mid-section. Fig. 2 is an end elevationthereof partly in vertical section on the line 2-2 in Fig. 1. Fig.3 is avertical longitudinal section of the lower portion of the apparatus on alargerscale. Fig.4 is an end elevation partly in vertical transversemidsection, showing the gearfor lifting and lowering the mounting forthe calcining chamber. Fig. 5 is a partial section of the right hand endof Fig. 3, construction. Fig. 6 is an enlarged detail view of thenozzle. I

Referring to the drawings, letA designate the furnace or combustionchamber and B the chimney or-stack. The furnace A consists of a rotarycalcining-chamber A and means for supplying combustible gas or fuelthereto and for elfecting the ignition of such fuel. The stack B isbuilt preferably of solid mashowing, however, a modified sonry in anymanner-common in the building .of chimneys, and extends to a suitableheight to afford the requisitedraft. At its lower end, and below theopening a, through which it communicates with *th'e'calcining chamber A,it is provided withka pit O constituting a concentrating "tank for thealkaline solution. This tank is preferably constructed with a metalshell and a brick lining. The rotary chamber A is constructed with itsoutlet end b which communicates with the opening a in the stack, toproject into a recess a formed around this opening so as to make asuitablv close connection or joint between the revolviing chamber andthe stationary stack. The opposite end of the chamber is closed by ashield D, formed with an opening 61 through which a stream of burningfuel in the form of gas or a sprayof liquid is introduced from a burnerE. The shield D is mounted in any suitable manner by means of which itmay 45 through a stuffing boxjand is revolved by a H, and the pipeleading to it; with a door 8 f in this pipe, Fig. 3 which is opened orclosed by a float g working in a standpipe h which is in communicationwith the tank 0. As the level is lowered in the tank 0 by the solutiontherein flowing off into the calcining chamber A, the descent of thefloat g opens the valve f and admits sufficient fresh liquid to restorethe normal level. The denser liquid is drawn off from the bottom of thetank 0 through a pipe 1', an dis forced bya pump G up through a pipe 2"to a spraying nozzle H arranged at some suitable heiglit within thestack B, the flow being regulated by a valve j. The nozzle H may be ofany suitable construction adapted either to spray or subdivide theliquid and thereby cause it to shower downthrough the stack, or todeflect it against the walls of the stack so that it shall be caused tostream down against the heated walls. The simpleconstruction shown inFig. 6 may be used consisting merely of the down-turned open end of thepipe i, and beneath ita spatter-platef by which the liquid is deflectedand the greater part of it is thrown against the walls of the,

Other formsof nozzles or spray-valves stack.

may, however, be substituted. The liquid during its descent through thestack is evaporated tomuch greater density and falls back into the tankC. By the operation of the 7 pump the liquid is being continuallycirculated through this tank, and from the-bottom thereof into thestack,so that it is rapidly' concentrated. The liquid in the tank iskept stirred by an agitator or stirring arms 76 mounted on an uprightshaft having a bearing at its upper end in the cross frame l, and

driven through bevel gears m from a horizontal shaft m whichenters theside ofthe tank belt on a pulley n, or by other means.

The tank C is provlded with an outlet passage pfor conducting theconcentrated solution into the calcining chamber. This ispreferablyconstructed as a pipe incased in apro-.

jecting arm I of masonry, which projects through the outlet or throat I)of the revolving chamber A, so that the stream flowing the overflow willtake place and whereby the overflow of the liquidinto'the recess a andout through the joint between the stack and chamber A, will be-avoided.The most concentrated liquid which has last flowed from the stack intothe tank, and which floats for a time on top of the liquid therein, isswept In case the passage off by the upper stirrer la and passes outthrough the passage 19 tothe calcining chamber. Only a portion of theconcentrated liquid thus falling is discharged in this manner, theremainder being mixed with the remaining liquor in the tank and againdrawn off from the bottom thereof, so that a continual circulation ismaintained in the tank. The adjustment of the float g determines thelevel in the tank 0, and consequently the rate of flow of the liquid outtherefrom into the calcining chamber, and consequently also the rate offlow of fresh liquid into the tank.

By the location of the tank 0 close to the outlet from the calciningchamber A. the liquid contained in it is subjected to the heat of theburning gases flowing from this cham her into the stack, so that theheat of the fuel, as well as the heat generated by the burning of theligneous and mucilaginous matters contained in the material undergoingcalcination, is most thoroughly utilized for the concentration of theliquor being prepared for calcination.

By the streaming of the liquor to be concentrated down the walls of thestack, the latter is utilized not only as a chimney or flue but also asa concentrating chamber. This stack or chamber is preferably vertical,but might be inclined. At the top of the stack is placed a vaporseparator J consisting of a. plate or disk mounted at a suitabledistance above the top of the stack where it will serve to intercept anddeflect the stream of ascending gases and thereby cause any spray dustor solid matter to be disengaged. The matter thus separated is caught ina chamber Ksurrounding the top of the stack and inclosing the separatorJ. This chamber may be washed out by flowing liquor into it from a pipe71 constituting an upward continuation of'the pipe 'L' from the pump G.The washings, carrying with them any alkaline particles, will run fromthe chamber through holes q q, and pass down the stack. The stack isprovided with a door r to provide access to the nozzle to provide accessto the tank 0; and with an opening t through which to introduce a-pipefor conveying gaseous or liquid fuel in order to introduce a furtherproportion of combustible into the stack for the purpose of betterperforming the evaporation or concentration of the liquid.

Under the pump G is constructed a saveall tank L which serves to catchany liquid that may leak from the pumporfrom any pipes or joints. Inorder to catch any material that may find its way through the recess 0and joint between the revolving calcining chamber A and stack B, aspecial passage q is provided which leads suchleakage into the save-allL.

The rotary calcining chamber A is constructed in any usual or suitablemanner, an outer shell of iron lined with fire-brick being preferable.The outer shell carries annular ICC rails which roll on supportingflanged-wheels a fixed on two shafts a at either side. On one of theseshafts is fixed a sprocket-wheel b driven by a chain 6 from a similarsprocketwheel on a shaft Bythis means the chamber A is caused torevolve.

The revolving chamber A is mounted on a supporting frame M pivoted ontrunnions at m and provided with means for raising and lowering itsopposite or free end, whereby it may be moved to any suitableinclination, and thereby the chamber A may be tilted to anyextentdesired. This is an important and desirable feature, as it enables thespeed of travel through the chamber of the material undergoingcalcination to be governed at will. The frame M is preferablyconstructedof longitudinal girders resting on the trunnions at .one end andconnected with a lifting apparatus at the other, and with transversegirders over them on which rest the bearings of the shafts a as clearlyshown; Any other suitable construction of frame may be provided, itbeing only essential that the frame shall properly support the calciningchamber through the medium of the shafts over which it is rotativelymounted, and shall be pivotally mounted so that it may betilted orrocked to different angles. The trunnions m might be otherwise arranged,but it is preferable to place them as near to the end I) of the chamberas practicable, as thereby the tilting of the chamber exerts the leasteffect to open or close the joint 0 between the chamber and the masonryof the stack.

For tilting the frame M any suitable mechanism may be employed, such asadjusting screws wedges, chain pulleys or block and tackle. The meanswhich I prefer consists of vertical adjusting screws from which the freeends of the longitudinal beams of the frame are hung. This mechanism isshown in Figs. 3 and 4. I prefer to use two adjusting screws lettered NN, on the lower ends of which the longitudinal beams are hung throughlinks The screws are engaged by female screw-threads formed in the hubsof wormwheels 0 O, which are engaged by worms on a transverse shaft P,which may be turned by a hand wheel P. The wheels 0 0 have a solidbearing on a frame Q resting on masonry or other suitable support. Byturning the handle 1? the two screws are propelled up or downsimultaneously and the supporting frame is thereby tilted to any angledesired.

The operation of calcining in the chamber A is the same as in otherrotary calcining furnaces. The only difference is that whereasheretofore the calcining chamber has been mounted at a certaininvariable angle so that the passage of the soda liquor and itsresultant the calcined ash through the chamber could not be regulated,by my construction of the chamber to be adjustable the rapidity of thepassage of material through it may be regulated to a nicety as may fromtime to time be found desirable. The calcined material or ash as it isdelivered from the calcining chamber falls out from the end thereofbeneath the shield D, or through the space between the shield and theend of the chamber, and drops through the frame-work M into a conveyortrough R, wherein it is drawn along to any suitable point by means of ashoe or plate r or by any known or suitable construction of con veyer,the details of which are immaterial. The shield D is supported on thesame framework M as the chamber A, so that it is tilted with the latter.For supporting it I provide a frame S mounted on the frame M, over whichare mounted transverselysliding frames S', and on which are againmounted a longitudinally sliding frame S to which the shield D is fixed.By means of these frames the shield D may he slid backwardly and toeither side in order'to get access to the interior of the chamber A.When solid fuel is to be used, I provide in place of the shieldD andburner d a separate initial combustion chamber D for burning the solidfuel, as shown in Fig. 5. This may be made of masonry and of anysuitable construction, with grate-bars 'L6 and bridge wall it, the spaceover which communicates with the end of the chamber A. This furnace ismounted through the medium of frames S, S, S upon the frame-work M inthe same manner as the shield D, of which it constitutes the equivalent,the function of each being to partially close the discharge end of therevolving chamber A, and to sup ply ignited fuel thereto. By adjustingthe shield D or furnace D to cause it to approach or recede from thechamber A, the admission of air through the space between may beadjusted to the extent desired.

My invention is not limited to the exact details of construction hereinshown, as the same may be greatly modified. Those features of myinvention which I consider essential are hereinafter defined in theclaims. Those features of my invention which pertain to theconcentrating of the solution before its calcination are not limited intheir application to rotary calcining furnaces, but are equallyapplicable to those furnaces wherein the calcining chamber isstationary.

A furnace for concentrating alkaline or other solutions by showering orstreaming down the walls of an upright chamber or stack, is claimed inmy patent No. 478,981, granted July 18, 1892.

My present application for patent relates to the same subject matter ofinvention as another application for patent for furnace for evaporatingand calcining alkaline and other solutions, filed by me March 19, 1892,

Serial No. 425,543, and still pending; I make 1 no claim herein toanything claimed in that application.

I claim as my invention the following defined novel features orimprovements, substantially as hereinbefore specified, namely:

1. A calcining furnace consisting of a calcining chamber and an uprightstack, a tank at the base of said stack for receiving the solution to becalcined, a pump for drawing off the solution from said tank, and a pipeleading from the outlet of said pump and discharging into said stack,whereby the liquid is circulated in said tank, and repeatedly showereddown the stack and returned into said tank preparatory to beingdischarged into the calcining chamber.

2. In a calcining furnace, the combination of an upright stack, aconcentrating tank built into the base of the stack, a revolvingcalcining chamber having an outlet opening communicating with the baseof the stack, and the base of the stack formed with an arm project-. inginto the calcining chamber, and with an outlet passage from said tankthrough said arm for delivering the concentrated solution from said tankinto the calcining chamber.

' 3. In a calcining furnace, the combination of an upright stack, aconcentrating tank built into the base of the stack,a revolving calcin--ing chamber having an outlet opening communicating with the base of thestack, and the base of the stack formed with an arm projecting into thecalcining chamber, and with an outlet passage from said tank throughsaid arm for delivering the concentrated solution from said tank intothe calcining chamber, and said arm formed with a depression orchannelon its upper side through which the solution may flow in case of thestoppage of said passage, and whereby the overflow of the solutionintothe joint or space between the revolving chamber and the stack isprevented.

4. In a calcining furnace, the combination with the calciningchamber-and stack of a concentrating tank built within the base of thestack, an outlet therefrom to the calcining chamber, a standpipeexterior to the furnace and communicating with said tank, a supply tankand pipe extending therefrom to said concentrating-tank, a valve in saidpipe, and a float in said standpipe for automatically operating saidValve and thereby controlling the height of liquid in the concentratingtank.

5. In a calcining furnace, thecombination of a calcining chamber andstack, a concen-' trating tank within the furnace, an agitator withinsaid tank, a pump for drawing off the solution from said tank, and apipe leading from the outlet of said pump and discharging the solutioninto the stack, whereby the solution in said tank is agitated andisrepeatedly circulated from said tankand streamed down the stack.

6. In a calcining furnace, the combination of a calcining chamber andstack, a concentrating tank within the furnace, an upright shaftcarrying stirring arms within said tank, a driving shaft passinglaterally through said tank, and bevel gears within the tank forcommunicating motion from said driving shaft to said stirrer shaft,whereby the material in said tank may be efiectively agitated andcommingled.

with an upright stack and means for showering the solution to beconcentrated down through said stack, of a separator for recovering anyparticles which might otherwise be carried out through the top of thestack, consisting of a deflecting plate mounted'above the top of thestack, a collecting chamber arranged to inclose the upper end of thestack and receive any particles disengaged by said plate, and means forwashing down any material collected by said chamber, consisting of apipe for conveying liquid thereinto, and an opening from the bottom ofsaid chamber into the stack, whereby the liquid directed into saidchamber washes the recovered particles through said opening and down thestack.

8. The combination of a stationarystack, a horizontal furnace comprisingas part thereof a revolving calcining chamber having its receivingendcommunicating with said stack, and arranged to discharge the calcinedmaterial from its opposite end, a tilting framework for supporting saidfurnace and tilting it to varying angles, pivoted adjacent to thereceiving end ofsaid chamber, and mechanism for'raisin-g or loweringsaid framework to raise or lower the discharge end of said chamber atwill.

9. The combination of a'stationary stack, a

horizontal furnace comprising a revolving calcining chamber having itsreceiving end communicating with said stack, and means at its oppositeor discharge end for partially closing it and for supplying ignited fuelto it, a tilting framework for supporting said furnace and tilting it tovarying angles, pivoted adjacent to the receiving end of .said chamber,and mechanism for raising or lowering said frameworkto raise or lowerthe discharge end of said chamber at will.

10. The combination of a stationary stack, a horizontal furnacecomprising a revolving calcining chamber having its receiving endcommunicating with said stack, and a stationary shield or initialcombustion chamber at its opposite or discharge end for partiallyclosing it and having an opening for supplying ignited fuel to it, thesupporting wheels and shafts of said rotary chamber, a support for saidstationary shield or chamber, a tilting framework for supporting saidfurnace, on which said wheels and'shafts and said support are mounted,and mechanism for raising or loweringsaid framework to tilt it todifferent angles at will. 4

11. The combination of a stationary stack,

IIO

a horizontal furnace comprising a-revolving charge end of the rotarychamber, a tilting framework for supporting said furnace, on which saidwheels and shafts and said support are mounted,and mechanism for tiltingsaid framework to different angles at will.

12. The combination with a revolving calcining chamber and its shield orinitial combustion chamber, a tilting platform supporting them, and alifting mechanism therefor consisting of upright screws to which theends of the longitudinal beams of the platform are connected, wormwheels having threaded hubs engaging said screws, and a transverse shafthaving worms meshing with said worm-Wheels.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses. I

HENRY BLACKMAN. Witnesses:

GEORGE H. FRASER, ARTHUR C. FRASER.

